/* ============================================================
   CRUMB — Main Application Styles (app.css)
   Offline Knowledge Vault & Memory Bread Interface
   ============================================================ */

/* App Layout Container */
.app-viewport {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  background: var(--cream);
  color: var(--ink);
  position: relative;
}

/* App Header */
.app-header {
  height: 64px;
  flex: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  background: rgba(247, 240, 225, 0.85);
  backdrop-filter: blur(20px) saturate(1.4);
  -webkit-backdrop-filter: blur(20px) saturate(1.4);
  border-bottom: 1px solid var(--line);
  z-index: 100;
}

.app-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.app-brand .brand-name {
  color: var(--navy) !important;
  font-weight: 700;
  font-family: var(--font-display);
  font-size: 1.35rem;
  letter-spacing: 0.04em;
}
.app-brand .brand-name em {
  color: var(--amber) !important;
  font-style: normal;
}

.offline-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 14px;
  border-radius: var(--radius-pill);
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  background: rgba(237, 166, 62, 0.14);
  border: 1px solid rgba(237, 166, 62, 0.35);
  color: #7a4e12;
  transition: all 0.3s var(--ease-out);
}

.offline-pulse {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--amber-bright);
  box-shadow: 0 0 10px rgba(237, 166, 62, 0.9);
  animation: glowPulse 2s ease-in-out infinite;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Emergency Mode Toggle Button */
.btn-emergency-toggle {
  background: rgba(192, 90, 74, 0.12);
  border: 1px solid rgba(192, 90, 74, 0.35);
  color: #933224;
  transition: all 0.3s var(--ease-out);
}
.btn-emergency-toggle:hover, .btn-emergency-toggle.active {
  background: #c05a4a;
  color: #fff;
  border-color: #a33e30;
  box-shadow: 0 0 20px rgba(192, 90, 74, 0.4);
}

/* Main 3-Column Workspace Grid */
.app-main {
  flex: 1;
  display: grid;
  grid-template-columns: 320px 1fr 380px;
  min-height: 0; /* Important for inner scroll */
  position: relative;
  overflow: hidden;
}

/* ------------------------------------------------------------
   LEFT PANEL: Knowledge Library & Slices
   ------------------------------------------------------------ */
.panel-left {
  background: linear-gradient(180deg, rgba(247, 240, 225, 0.6) 0%, rgba(239, 228, 203, 0.8) 100%);
  border-right: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.panel-header {
  padding: 18px 20px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid rgba(226, 211, 178, 0.6);
}

.panel-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--navy);
  display: flex;
  align-items: center;
  gap: 8px;
}

.search-box {
  padding: 12px 18px;
  position: relative;
}

.search-input {
  width: 100%;
  padding: 9px 14px 9px 36px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line);
  background: rgba(255, 252, 245, 0.7);
  font-size: 0.85rem;
  color: var(--ink);
  transition: all 0.25s var(--ease-out);
  outline: none;
}
.search-input:focus {
  border-color: var(--amber-bright);
  background: #fff;
  box-shadow: 0 0 0 3px rgba(237, 166, 62, 0.2);
}

.search-icon {
  position: absolute;
  left: 30px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--ink-soft);
  pointer-events: none;
}

/* Slices Scroll Area */
.slices-list {
  flex: 1;
  overflow-y: auto;
  padding: 10px 18px 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.slice-item {
  position: relative;
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, #fdf8eb, #f2e5c6);
  border: 1px solid rgba(255, 255, 255, 0.85);
  box-shadow: 0 10px 24px -14px rgba(64, 44, 14, 0.35);
  padding: 14px 16px;
  cursor: grab;
  user-select: none;
  display: flex;
  align-items: center;
  gap: 14px;
  transition: transform 0.3s var(--ease-spring), box-shadow 0.3s var(--ease-out), border-color 0.3s;
}

.slice-item::after {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 10px;
  background: linear-gradient(180deg, rgba(201, 138, 46, 0.4), rgba(201, 138, 46, 0));
  border-radius: var(--radius-md) var(--radius-md) 0 0;
  opacity: 0.6;
}

.slice-item:hover {
  transform: translateY(-3px) scale(1.01);
  box-shadow: 0 16px 32px -16px rgba(64, 44, 14, 0.45);
}

.slice-item.in-tray {
  border-color: var(--amber-bright);
  background: linear-gradient(160deg, #fff7e6, #fcebc4);
  box-shadow: 0 0 0 2px rgba(237, 166, 62, 0.4), 0 12px 28px -12px rgba(201, 138, 46, 0.5);
}

.slice-item.in-tray .slice-active-dot {
  opacity: 1;
  transform: scale(1);
}

.slice-active-dot {
  position: absolute;
  top: 10px;
  right: 10px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--amber-bright);
  color: #1c1205;
  font-size: 0.65rem;
  font-weight: 800;
  display: grid;
  place-items: center;
  box-shadow: 0 0 10px rgba(237, 166, 62, 0.8);
  opacity: 0;
  transform: scale(0.4);
  transition: all 0.3s var(--ease-spring);
}

.slice-content {
  flex: 1;
  min-width: 0;
}
.slice-title {
  font-weight: 650;
  font-size: 0.92rem;
  color: var(--navy);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.slice-sub {
  font-size: 0.74rem;
  color: var(--ink-soft);
  margin-top: 2px;
}

/* Upload Button Bottom */
.panel-left-footer {
  padding: 16px 18px;
  border-top: 1px solid var(--line);
  background: rgba(247, 240, 225, 0.9);
}

.btn-upload-slice {
  width: 100%;
  justify-content: center;
  border: 1.5px dashed var(--amber);
  background: rgba(253, 246, 228, 0.8);
  color: var(--crust);
}
.btn-upload-slice:hover {
  background: rgba(237, 166, 62, 0.15);
  border-color: var(--amber-bright);
  color: var(--navy);
}

/* ------------------------------------------------------------
   CENTER PANEL: Conversation Interface & Memory Tray
   ------------------------------------------------------------ */
.panel-center {
  display: flex;
  flex-direction: column;
  background: var(--cream);
  min-height: 0;
  position: relative;
}

/* Memory Tray Section */
.memory-tray-bar {
  padding: 14px 24px;
  background: linear-gradient(180deg, rgba(239, 228, 203, 0.5) 0%, rgba(247, 240, 225, 0.3) 100%);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: 16px;
  transition: all 0.4s var(--ease-out);
}

.memory-tray-bar.glow {
  background: linear-gradient(180deg, rgba(237, 166, 62, 0.18) 0%, rgba(247, 240, 225, 0.5) 100%);
  box-shadow: inset 0 -1px 0 rgba(237, 166, 62, 0.4), 0 8px 24px -12px rgba(237, 166, 62, 0.4);
}

.tray-label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--navy);
  flex: none;
}

.tray-dropzone {
  flex: 1;
  min-height: 48px;
  border-radius: var(--radius-md);
  border: 1.5px dashed rgba(201, 138, 46, 0.4);
  background: rgba(255, 252, 245, 0.6);
  padding: 6px 12px;
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
  transition: all 0.3s var(--ease-out);
}

.tray-dropzone.drag-over {
  border-color: var(--amber-bright);
  background: rgba(237, 166, 62, 0.2);
  box-shadow: 0 0 20px rgba(237, 166, 62, 0.4);
}

.tray-empty-hint {
  font-size: 0.8rem;
  color: var(--ink-soft);
  padding: 0 8px;
  font-style: italic;
}

.tray-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border-radius: var(--radius-pill);
  background: linear-gradient(135deg, #fff7e6, #fbe8c2);
  border: 1px solid var(--amber-bright);
  font-size: 0.78rem;
  font-weight: 600;
  color: #4a2e06;
  box-shadow: 0 2px 8px rgba(201, 138, 46, 0.25);
  animation: popIn 0.3s var(--ease-spring);
}

.tray-chip-remove {
  cursor: pointer;
  opacity: 0.6;
  transition: opacity 0.2s;
  display: grid;
  place-items: center;
}
.tray-chip-remove:hover { opacity: 1; color: #c05a4a; }

/* Conversation History */
.conversation-area {
  flex: 1;
  overflow-y: auto;
  padding: 24px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.chat-welcome {
  max-width: 580px;
  margin: 30px auto;
  text-align: center;
  padding: 32px 28px;
  border-radius: var(--radius-lg);
  background: rgba(255, 252, 245, 0.65);
  border: 1px solid rgba(255, 255, 255, 0.8);
  box-shadow: var(--shadow-soft);
}

.welcome-icon {
  width: 54px;
  height: 54px;
  margin: 0 auto 16px;
  border-radius: 16px;
  background: linear-gradient(145deg, var(--amber-bright), var(--amber));
  display: grid;
  place-items: center;
  box-shadow: var(--shadow-glow);
}

.welcome-title {
  font-family: var(--font-display);
  font-size: 1.5rem;
  color: var(--navy);
  margin-bottom: 8px;
}

.welcome-sub {
  font-size: 0.92rem;
  color: var(--ink-soft);
  margin-bottom: 22px;
}

.prompt-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.prompt-btn {
  padding: 8px 14px;
  border-radius: var(--radius-pill);
  background: #fff;
  border: 1px solid var(--line);
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--navy);
  transition: all 0.25s var(--ease-spring);
}
.prompt-btn:hover {
  border-color: var(--amber);
  background: var(--cream-2);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px -6px rgba(201, 138, 46, 0.3);
}

/* Chat Messages */
.message-row {
  display: flex;
  gap: 14px;
  max-width: 860px;
  animation: fadeIn 0.4s var(--ease-out);
}

.message-row.user {
  flex-direction: row-reverse;
  align-self: flex-end;
}

.message-row.assistant {
  align-self: flex-start;
}

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 12px;
  display: grid;
  place-items: center;
  flex: none;
  font-weight: 700;
  font-size: 0.85rem;
}

.message-avatar.user-avatar {
  background: var(--navy-2);
  color: var(--cream);
}

.message-avatar.assistant-avatar {
  background: linear-gradient(135deg, var(--amber-bright), var(--amber));
  color: #1c1205;
  box-shadow: 0 4px 12px rgba(201, 138, 46, 0.4);
}

.message-bubble {
  max-width: 720px;
  padding: 16px 20px;
  border-radius: var(--radius-md);
  font-size: 0.93rem;
  line-height: 1.65;
  position: relative;
}

.message-row.user .message-bubble {
  background: linear-gradient(145deg, var(--navy-2), var(--navy-1));
  color: var(--cream);
  border-bottom-right-radius: 4px;
  box-shadow: 0 10px 24px -10px rgba(11, 24, 41, 0.4);
}

.message-row.assistant .message-bubble {
  background: rgba(255, 252, 245, 0.9);
  border: 1px solid rgba(255, 255, 255, 0.85);
  color: var(--ink);
  border-bottom-left-radius: 4px;
  box-shadow: var(--shadow-soft);
}

.message-meta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 10px;
  padding-top: 8px;
  border-top: 1px solid rgba(226, 211, 178, 0.4);
  font-size: 0.74rem;
  color: var(--ink-soft);
}

.offline-badge-sm {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  border-radius: var(--radius-pill);
  background: rgba(237, 166, 62, 0.15);
  color: #8c550e;
  font-weight: 600;
}

.message-source-tag {
  background: rgba(43, 54, 68, 0.08);
  padding: 2px 8px;
  border-radius: 4px;
}

/* Chat Input Bar */
.chat-input-container {
  padding: 16px 24px 20px;
  background: rgba(247, 240, 225, 0.8);
  border-top: 1px solid var(--line);
}

.chat-form {
  position: relative;
  display: flex;
  align-items: center;
}

.chat-textarea {
  width: 100%;
  padding: 14px 54px 14px 20px;
  border-radius: var(--radius-md);
  border: 1.5px solid var(--line);
  background: #fff;
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--ink);
  resize: none;
  outline: none;
  min-height: 52px;
  max-height: 140px;
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.02);
  transition: all 0.25s var(--ease-out);
}

.chat-textarea:focus {
  border-color: var(--amber-bright);
  box-shadow: 0 0 0 3px rgba(237, 166, 62, 0.25), inset 0 1px 2px rgba(0, 0, 0, 0.02);
}

.chat-send-btn {
  position: absolute;
  right: 10px;
  width: 38px;
  height: 38px;
  border-radius: 12px;
  border: none;
  background: linear-gradient(135deg, var(--amber-bright), var(--amber));
  color: #1c1205;
  display: grid;
  place-items: center;
  cursor: pointer;
  box-shadow: 0 4px 12px rgba(201, 138, 46, 0.4);
  transition: all 0.25s var(--ease-spring);
}

.chat-send-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 16px rgba(201, 138, 46, 0.6);
}

.chat-send-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none;
}

/* ------------------------------------------------------------
   RIGHT PANEL: Memory Imprint View
   ------------------------------------------------------------ */
.panel-right {
  background: linear-gradient(180deg, rgba(247, 240, 225, 0.6) 0%, rgba(239, 228, 203, 0.8) 100%);
  border-left: 1px solid var(--line);
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.imprint-tabs {
  display: flex;
  border-bottom: 1px solid var(--line);
  background: rgba(247, 240, 225, 0.8);
  padding: 6px 12px 0;
  gap: 4px;
}

.tab-btn {
  flex: 1;
  padding: 10px 8px;
  border: none;
  background: transparent;
  font-family: inherit;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--ink-soft);
  border-bottom: 2.5px solid transparent;
  cursor: pointer;
  transition: all 0.25s;
  text-align: center;
  white-space: nowrap;
}

.tab-btn:hover {
  color: var(--ink);
}

.tab-btn.active {
  color: var(--navy);
  border-bottom-color: var(--amber-bright);
}

.imprint-content {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
}

/* Tab 1: Key Takeaways & Summaries */
.takeaway-card {
  border-radius: var(--radius-md);
  background: #fff;
  border: 1px solid var(--line);
  padding: 16px 18px;
  margin-bottom: 14px;
  box-shadow: 0 4px 14px -6px rgba(0, 0, 0, 0.05);
}

.takeaway-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 10px;
}

.takeaway-tag {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--amber);
}

.takeaway-list {
  padding-left: 18px;
  font-size: 0.88rem;
  color: var(--ink);
  line-height: 1.6;
}

.takeaway-list li {
  margin-bottom: 6px;
  list-style: disc;
}

/* Tab 2: Interactive Flashcards */
.flashcard-container {
  perspective: 1000px;
  min-height: 240px;
  margin-bottom: 16px;
}

.flashcard-inner {
  width: 100%;
  min-height: 240px;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.6s var(--ease-spring);
  cursor: pointer;
}

.flashcard-inner.flipped {
  transform: rotateY(180deg);
}

.flashcard-face {
  position: absolute;
  inset: 0;
  border-radius: var(--radius-md);
  padding: 24px;
  backface-visibility: hidden;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-card);
  border: 1px solid rgba(255, 255, 255, 0.9);
}

.flashcard-front {
  background: linear-gradient(160deg, #fdf8eb, #f2e5c6);
  color: var(--navy);
}

.flashcard-back {
  background: linear-gradient(160deg, var(--navy-3), var(--navy-1));
  color: var(--cream);
  transform: rotateY(180deg);
}

.card-topic {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0.75;
}

.card-text {
  font-family: var(--font-display);
  font-size: 1.15rem;
  line-height: 1.4;
  margin: 14px 0;
}

.card-hint {
  font-size: 0.76rem;
  opacity: 0.7;
  text-align: right;
}

.flashcard-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
}

.btn-card-action {
  flex: 1;
  padding: 8px 12px;
  border-radius: var(--radius-pill);
  font-size: 0.8rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.2s;
}
.btn-card-action:active { transform: scale(0.96); }

.btn-again { background: rgba(192, 90, 74, 0.15); color: #933224; }
.btn-easy { background: rgba(90, 169, 79, 0.18); color: #235c1b; }

/* Tab 3: Interactive Quizzes */
.quiz-box {
  background: #fff;
  border-radius: var(--radius-md);
  border: 1px solid var(--line);
  padding: 20px;
  box-shadow: 0 4px 16px -6px rgba(0, 0, 0, 0.05);
}

.quiz-question {
  font-weight: 650;
  font-size: 0.95rem;
  color: var(--navy);
  margin-bottom: 16px;
  line-height: 1.45;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.quiz-option-btn {
  padding: 10px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--line);
  background: var(--cream-2);
  text-align: left;
  font-size: 0.86rem;
  font-weight: 500;
  color: var(--ink);
  cursor: pointer;
  transition: all 0.2s;
}

.quiz-option-btn:hover {
  border-color: var(--amber);
  background: #fff;
}

.quiz-option-btn.correct {
  background: #e6f4e6;
  border-color: #5aa94f;
  color: #1e5218;
  font-weight: 600;
}

.quiz-option-btn.incorrect {
  background: #fde8e5;
  border-color: #c05a4a;
  color: #701d14;
}

.quiz-feedback {
  margin-top: 14px;
  padding: 10px 12px;
  border-radius: 8px;
  font-size: 0.82rem;
  line-height: 1.45;
}
.quiz-feedback.success { background: #eaf6ea; color: #1e5218; }
.quiz-feedback.error { background: #fceae8; color: #701d14; }

/* Tab 4: Knowledge Graph Visualizer */
.graph-container {
  width: 100%;
  height: 300px;
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, var(--navy-2), var(--navy-1));
  position: relative;
  overflow: hidden;
  border: 1px solid rgba(255, 240, 210, 0.1);
}

#graphCanvas {
  width: 100%;
  height: 100%;
  display: block;
}

/* ------------------------------------------------------------
   EMERGENCY KNOWLEDGE MODE OVERLAY / STATE
   ------------------------------------------------------------ */
.app-viewport.emergency-active {
  background: #090e17;
  color: #e2e8f0;
}

.app-viewport.emergency-active .app-header {
  background: rgba(13, 22, 35, 0.92);
  border-bottom-color: rgba(237, 166, 62, 0.3);
}

.app-viewport.emergency-active .panel-left,
.app-viewport.emergency-active .panel-right {
  background: linear-gradient(180deg, #0d1726, #090f19);
  border-color: rgba(255, 240, 210, 0.1);
}

.app-viewport.emergency-active .panel-center {
  background: #090e17;
}

.app-viewport.emergency-active .panel-title,
.app-viewport.emergency-active .slice-title,
.app-viewport.emergency-active .welcome-title,
.app-viewport.emergency-active .tray-label {
  color: #f7fafc;
}

.app-viewport.emergency-active .slice-item {
  background: linear-gradient(160deg, #162438, #0f1a2a);
  border-color: rgba(237, 166, 62, 0.25);
  color: #e2e8f0;
}

.app-viewport.emergency-active .slice-sub {
  color: #94a3b8;
}

.app-viewport.emergency-active .message-row.assistant .message-bubble {
  background: #152438;
  border-color: rgba(237, 166, 62, 0.25);
  color: #f1f5f9;
}

.app-viewport.emergency-active .chat-textarea {
  background: #111d2e;
  border-color: rgba(237, 166, 62, 0.3);
  color: #f8fafc;
}

.app-viewport.emergency-active .takeaway-card,
.app-viewport.emergency-active .quiz-box {
  background: #121f31;
  border-color: rgba(255, 240, 210, 0.12);
  color: #e2e8f0;
}
.app-viewport.emergency-active .quiz-question { color: #f8fafc; }

/* ------------------------------------------------------------
   TOAST NOTIFICATIONS
   ------------------------------------------------------------ */
.toast-container {
  position: fixed;
  bottom: 24px;
  right: 24px;
  z-index: 10000;
  display: flex;
  flex-direction: column;
  gap: 10px;
  pointer-events: none;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius-pill);
  background: var(--navy-3);
  color: var(--cream);
  font-size: 0.85rem;
  font-weight: 550;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  border: 1px solid rgba(237, 166, 62, 0.4);
  animation: popIn 0.35s var(--ease-spring);
  display: flex;
  align-items: center;
  gap: 10px;
  pointer-events: auto;
}

.toast-icon {
  color: var(--amber-bright);
}

/* Modal for File Upload & Details */
.modal-backdrop {
  position: fixed;
  inset: 0;
  z-index: 9999;
  background: rgba(11, 24, 41, 0.65);
  backdrop-filter: blur(12px);
  display: grid;
  place-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s;
}

.modal-backdrop.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-card {
  width: min(540px, 92vw);
  background: var(--cream);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.8);
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.35);
  padding: 30px;
  position: relative;
  transform: scale(0.92);
  transition: transform 0.3s var(--ease-spring);
}

.modal-backdrop.active .modal-card {
  transform: scale(1);
}

.modal-close {
  position: absolute;
  top: 20px;
  right: 20px;
  background: transparent;
  border: none;
  font-size: 1.3rem;
  color: var(--ink-soft);
  cursor: pointer;
}

/* Responsive adjustments */
@media (max-width: 1024px) {
  .app-main {
    grid-template-columns: 280px 1fr;
  }
  .panel-right {
    display: none; /* Can toggle via button */
  }
  .panel-right.show-mobile {
    display: flex;
    position: absolute;
    inset: 0 0 0 auto;
    width: 340px;
    z-index: 50;
    box-shadow: -10px 0 30px rgba(0,0,0,0.2);
  }
}

@media (max-width: 768px) {
  .app-main {
    grid-template-columns: 1fr;
  }
  .panel-left {
    display: none;
  }
  .panel-left.show-mobile {
    display: flex;
    position: absolute;
    inset: 0 auto 0 0;
    width: 290px;
    z-index: 50;
    box-shadow: 10px 0 30px rgba(0,0,0,0.2);
  }
}

/* ------------------------------------------------------------
   SLICE LAYER INSPECTOR (3D Isometric Stack & Particle Dough)
   ------------------------------------------------------------ */
.btn-inspect-slice {
  font-size: 0.72rem;
  padding: 3px 8px;
  border-radius: var(--radius-pill);
  background: rgba(201, 138, 46, 0.15);
  border: 1px solid rgba(201, 138, 46, 0.35);
  color: var(--crust);
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-inspect-slice:hover {
  background: var(--amber-bright);
  color: #1c1205;
}

.slice-inspector-modal {
  width: min(720px, 94vw);
  background: linear-gradient(160deg, #101c2c, #0a111e);
  color: var(--cream);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(237, 166, 62, 0.35);
  box-shadow: 0 30px 90px rgba(0, 0, 0, 0.75), var(--shadow-glow);
  padding: 32px;
  position: relative;
  overflow: hidden;
}

.inspector-canvas-bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
  opacity: 0.65;
}

.inspector-body {
  position: relative;
  z-index: 2;
}

.isometric-stack {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin: 24px 0 16px;
  perspective: 1000px;
}

.layer-card {
  border-radius: var(--radius-md);
  padding: 18px 22px;
  background: rgba(25, 42, 66, 0.75);
  border: 1px solid rgba(255, 240, 210, 0.15);
  backdrop-filter: blur(12px);
  box-shadow: 0 12px 30px rgba(0,0,0,0.4);
  transition: transform 0.4s var(--ease-spring), border-color 0.3s, box-shadow 0.3s;
  cursor: pointer;
}

.layer-card:hover {
  transform: translateY(-4px) scale(1.01);
  border-color: var(--amber-bright);
  box-shadow: 0 18px 40px rgba(237, 166, 62, 0.25);
}

.layer-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--amber-bright);
  margin-bottom: 6px;
}

.layer-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  color: #fff;
  margin-bottom: 8px;
}

.layer-blueprint-svg {
  width: 100%;
  max-height: 140px;
  background: rgba(10, 18, 30, 0.8);
  border-radius: var(--radius-sm);
  border: 1px dashed rgba(237, 166, 62, 0.4);
  padding: 12px;
  margin-top: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
}